It seem to go a step forward over Jolla's Other Half concept, where just the back (with extra/different functionalities, like i.e. hardware keyboard or more bat

It seem to go a step forward over Jolla's Other Half concept, where just the back (with extra/different functionalities, like i.e. hardware keyboard or more battery) is replaceable. Anyway, probably big companies will not want it, they want that you replace your phone from time to time. But small ones (i.e. chinese manufacturers wanting to make themselves an space) could grow a healthy ecosystem around this.